Large-area high-density plasma processing chamber for flat panel displays

ABSTRACT

Embodiments described herein provide a lid assembly of a chamber for independent control of plasma density and gas distribution within the interior volume of the chamber. The lid assembly includes a plasma generation system and a gas distribution assembly. The plasma generation system includes a plurality of dielectric plates having a bottom surface oriented with respect to vacuum pressure and a top surface operable to be oriented with respect to atmospheric pressure. One or more coils are positioned on or over the plurality of dielectric plates. The gas distribution assembly includes a first diffuser and a second diffuser. The first diffuser includes a plurality of first channels intersecting a plurality of second channels of the second diffuser.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending U.S. patent applicationSer. No. 16/400,923, filed May 1, 2019, which is herein incorporated byreference in its entirety.

BACKGROUND Field

Embodiments of the present disclosure generally relate to processchambers, such as plasma-enhanced chemical vapor deposition (PECVD)chambers. More particularly, embodiments of the present disclosurerelate to a lid assembly for process chambers.

Description of the Related Art

In the manufacture of solar panels or flat panel displays, manyprocesses are employed to deposit thin films on substrates, such assemiconductor substrates, solar panel substrates, and liquid crystaldisplay (LCD) and/or organic light emitting diode (OLED) substrates, toform electronic devices thereon. The deposition is generallyaccomplished by introducing a precursor gas into a chamber having asubstrate disposed on a temperature controlled substrate support. Theprecursor gas is typically directed through a gas distribution platesituated near the top of the chamber. The precursor gas in the chambermay be energized (e.g., excited) into a plasma by applying a radiofrequency (RF) power to a conductive showerhead disposed in the chamberfrom one or more RF sources coupled to the chamber. The excited gasreacts to form a layer of material on a surface of the substrate that ispositioned on the temperature controlled substrate support.

The size of the substrates for forming the electronic devices nowroutinely exceeds 1 square meter in surface area. Uniformity in filmthickness across these substrates is difficult to achieve. Filmthickness uniformity becomes even more difficult as the substrate sizesincrease. Traditionally, plasma is formed in the conventional chambersfor ionizing gas atoms and forming radicals of a deposition gas whichare useful for deposition of a film layer on substrates of this sizeusing a capacitively coupled electrode arrangement. Lately, interest ininductively coupled plasma arrangements, historically utilized indeposition on round substrates or wafers, is being explored for use indeposition processes for these large substrates. However, inductivecoupling utilizes dielectric materials as structural supportingcomponents. These dielectric materials do not have the structuralstrength to withstand structural loads created by the presence ofatmospheric pressure against one side of a large area structural portionof the chamber on the atmospheric side thereof, and to vacuum pressureconditions on the other side thereof, as used in the conventionalchambers for these larger substrates. Therefore, inductively coupledplasma systems have been undergoing development for large area substrateplasma processes. However, process uniformity, for example depositionthickness uniformity across the large substrate, is less than desirable.

Accordingly, what is needed in the art is a lid assembly of a chamberfor use on large area substrates that is configured to improve filmthickness uniformity across the deposition surface of a substrate.

SUMMARY

In one embodiment, a plate for a lid assembly is provided. The plateincludes a plasma generation system and a gas distribution assembly. Theplasma generation system has one or more cavities disposed in parallelin the plate. Each of the cavities includes recesses for a plurality ofdielectric plates. Each of the dielectric plates have a bottom surfaceoperable to be oriented with respect to a first pressure, and a topsurface operable to be oriented opposite to the bottom surface and withrespect to a second pressure different than the first pressure. One ormore coils are positioned on or over the plurality of dielectric plates.The gas distribution assembly includes a first diffuser. The firstdiffuser includes one or more first diffuser inlets disposed in theplate and a plurality of first channels in fluid communication with atleast one of the first diffuser inlets. Each first channel of theplurality of first channels is disposed in the plate and is adjacent toone of the recesses.

In another embodiment, a plate for a lid assembly is provided. The plateincludes a plasma generation system and a gas distribution assembly. Theplasma generation system has one or more cavities disposed in parallelin the plate. Each of the cavities includes recesses for a plurality ofdielectric plates. One or more coils are positioned on or over theplurality of dielectric plates. The gas distribution assembly includes afirst diffuser and a second diffuser. The first diffuser includes one ormore first diffuser inlets disposed in the plate and in fluidcommunication with a plurality of first channels. The second diffuserincludes one or more second diffuser inlets disposed in the plate and influid communication with a plurality of second channels. Each of thesecond channels is intersecting each of the first channels. Each of thedielectric plates is disposed adjacent to adjacent first channels and isdisposed adjacent to at least one of the second channels.

In yet another embodiment, a chamber is provided. The chamber includes achamber body, a substrate support disposed in the chamber body, and alid assembly plate positioned opposite the substrate support. The lidassembly plate and the substrate support define a processing region inthe chamber body. The lid assembly plate includes a plasma generationsystem and a gas distribution assembly. The plasma generation system hasone or more cavities disposed in parallel in the lid assembly plate.Each of the cavities includes recesses for a plurality of dielectricplates. Each of the dielectric plates has a bottom surface positioned inthe processing region and a top surface positioned outside theprocessing region. One or more coils are positioned on or over theplurality of dielectric plates. The gas distribution assembly includes afirst diffuser. The first diffuser includes one or more first diffuserinlets disposed in the lid assembly plate and a plurality of firstchannels in fluid communication with at least one the first diffuserinlets. Each first channel of the plurality of first channels isdisposed in the lid assembly plate and is adjacent to one of therecesses.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlyexemplary embodiments and are therefore not to be considered limiting ofits scope, and may admit to other equally effective embodiments.

FIG. 1 is a schematic cross-sectional view of a chamber according to anembodiment.

FIG. 2 is a schematic cross-sectional view of a plate according to anembodiment.

FIG. 3A is a schematic perspective view of a plate according to anembodiment.

FIG. 3B is a negative perspective view of a plate according to anembodiment.

FIG. 4 is a schematic bottom view of a plate according to an embodiment.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements and features of oneembodiment may be beneficially incorporated in other embodiments withoutfurther recitation.

DETAILED DESCRIPTION

Embodiments described herein provide a lid assembly of a chamber forindependent control of plasma density and gas distribution within theinterior volume of the chamber. The lid assembly includes a plasmageneration system and a gas distribution assembly. The plasma generationsystem includes a plurality of dielectric plates having a bottom surfaceoriented with respect to vacuum pressure and a top surface operable tobe oriented with respect to atmospheric pressure. One or more coils arepositioned on or over the plurality of dielectric plates. The gasdistribution assembly includes a first diffuser and a second diffuser.The first diffuser includes a plurality of first channels intersecting aplurality of second channels of the second diffuser.

FIG. 1 is a schematic cross-sectional view of a chamber 100, such as aPECVD chamber, that may benefit from embodiments described herein.Suitable chambers may be obtained from Applied Materials, Inc. locatedin Santa Clara, Calif. It is to be understood that the system describedbelow is an exemplary chamber and other chambers, including chambersfrom other manufacturers, may be used with or modified to accomplishaspects of the present disclosure. The chamber 100 includes a chamberbody, a lid assembly 106, and a substrate support assembly 108. The lidassembly 106 is disposed at an upper end of the chamber body 104.

The substrate support assembly 108 is at least partially disposed withinthe interior volume of the chamber body 104. The substrate supportassembly 108 includes a substrate support 110 and a shaft 112. Thesubstrate support 110 has a support surface 118 for supporting asubstrate 102. In one embodiment, which can be combined with otherembodiments described herein, the substrate 102 is a large areasubstrate, such as a substrate having a surface area of typically about1 square meter or greater. However, the substrate 102 is not limited toany particular size or shape. In one aspect, the term “substrate” refersto any polygonal, squared, rectangular, curved or otherwise non-circularworkpiece, such as a glass or polymer substrate used in the fabricationof flat panel displays, for example.

The substrate support 110 typically includes a heating element (notshown). The substrate support 110 is movably disposed within theinterior volume of the chamber body 104 by the shaft 112 which extendsthrough the chamber body 104 where the shaft 112 is connected to asubstrate support drive system 114. The substrate support drive system114 moves the substrate support 110 between an elevated processingposition (as shown) and a lowered position that facilitates substratetransfer to and from the interior volume of the chamber body 104 throughan opening 116 formed though the chamber body 104. In one embodiment,which can be combined with other embodiments described herein, thesubstrate support drive system 114 rotates the shaft 112 and thesubstrate support 110.

The lid assembly 106 includes a plate 122 that is disposed at an upperend of the chamber body 104. The plate 122 includes a gas distributionassembly 124 and a plasma generation system 126. The gas distributionassembly 124 includes one or more first diffuser inlets 130 of a firstdiffuser 128 disposed in the plate 122. In one embodiment, which can becombined with other embodiments described herein, the plate 122 includesaluminum-containing materials. In one embodiment, which can be combinedwith other embodiments described herein, the gas distribution assembly124 includes one or more second diffuser inlets (shown in FIG. 3A andFIG. 3B) coupled to a second diffuser 136 disposed in the plate 122. Theone or more first diffuser inlets 130 are coupleable to a first gassource 134. Each of the one or more first diffuser inlets 130 is influid communication with a first channel (shown in FIG. 3B) of the firstdiffuser 128. The one or more second diffuser inlets (shown in FIG. 3Aand FIG. 3B) are coupleable to a second gas source 138. Each of the oneor more second diffuser inlets (shown in FIG. 3A and FIG. 3B) is influid communication with a second channel (shown in FIG. 3B) of thesecond diffuser 136.

The first diffuser 128 delivers one or more first gases from the firstgas source 134 to a processing region 120 between a bottom surface 160of the plate 122 and the substrate support 110. The one or more firstgases are provided to the processing region 120 through a plurality offirst holes (shown in FIG. 4 ) of each first channel (shown in FIG. 3B)of the first diffuser 128. Flow controllers 141, such as a mass flowcontrol (MFC) devices, are disposed between each of the one or morefirst diffuser inlets 130 and the first gas source 134 to control flowrates of first gases from the first gas source 134 to each first channel(shown in FIG. 3B), and thus provide independent control of first gasflows in the processing region 120. The one or more second gases areprovided to the processing region 120 through a plurality of secondholes (shown in FIG. 4 ) of each second channel (shown in FIG. 3B) ofthe second diffuser 136. Flow controllers 141 are disposed between eachof the one or more second diffuser inlets (shown in FIG. 3A and FIG. 3B)and the second gas source 138 to control flow rates of second gases fromthe second gas source 138 to each second channel (shown in FIG. 3B), andthus provide independent control of second gas flows in the processingregion 120. A pump 155 is in fluid communication with the processingregion 120. The pump 155 is operable to control the pressure within theprocessing region 120 and to exhaust gases and byproducts from theprocessing region 120.

The plasma generation system 126 includes one or more cavities 140disposed in parallel in the plate 122. Each of the one or more cavities140 includes recesses (shown in FIGS. 2-4 ) for a plurality ofdielectric plates 150. Each of the one or more cavities 140 includes oneor more coils 142 positioned on or over the plurality of dielectricplates 150. The plurality of dielectric plates 150 provides a physicalbarrier having the structural strength to withstand structural loadscreated the presence of atmospheric pressure in the one or more cavities140 and the presence of vacuum pressure within the interior volume ofthe chamber body 104. Each of the plurality of dielectric plates 150includes a bottom surface 151 and a top surface 153 oriented opposite ofthe bottom surface 151. The bottom surface 151 is oriented with respectto (i.e., towards) the processing region 120 such that the bottomsurface 151 of each of the dielectric plates 150 is exposed to a firstpressure within the processing region 120, such as vacuum pressure. Thetop surface 153 is oriented opposite to (i.e., away from) the processingregion 120 such that the top surface 153 of each of the dielectricplates 150 is exposed to a second pressure outside of the processingregion 120, such as atmospheric pressure. In one embodiment, which canbe combined with other embodiments described herein, the first pressureand second pressure are different.

In one embodiment, which can be combined with other embodimentsdescribed herein, the dielectric plates include at least one of aluminumoxide (Al₂O₃), aluminum nitride (AlN), quartz, zirconium dioxide (ZrO₂),zirconium nitride (ZrN), quartz, and glass materials. Each coil 142 hasan electrical input terminal 144 connected to a power source 152 and anelectrical output terminal 146 connected to a ground 154. In oneembodiment, which can be combined with other embodiments describedherein, each coil 142 is connected to the power source 152 through amatch box 148 having a match circuit for adjusting electricalcharacteristics, such as impedance, of the coil 142. Each coil 142 isconfigured to create an electromagnetic field that energizes at leastone of the one of more first gases and second gases into an inductivelycoupled plasma. The independent connection of each coil 142 of each ofthe one or more cavities 140 to the respective power source 152 allowsfor independent control of the power level and frequency provided toeach coil 142. The independent control of the power level and frequencyprovided to each coil 142 allows for the density of the inductivelycoupled plasma to be independently controlled in the process zones 156a, 156 b, 156 c, 156 d (collectively referred to as process zones 156)corresponding to each coil 142. A controller 158 is coupled to thechamber 100 and configured to control aspects of the chamber 100 duringprocessing.

FIG. 2 is a schematic cross-sectional view of the plate 122. FIG. 2shows the one or more first diffuser inlets 130 of the first diffuser128 of the gas distribution assembly 124, and the one or more cavities140, each coil 142, each electrical input terminal 144, each electricaloutput terminal 146, and the recesses 201 for the plurality ofdielectric plates 150 of the plasma generation system 126. In oneembodiment, which can be combined with other embodiments describedherein, the lid assembly 106 includes a heat exchange system including aplurality of fluid channels (shown in FIG. 3B) coupleable to a heatexchanger (not shown). The heat exchanger, such as a chiller, is influid communication with each fluid channel via a fluid inlet 202 and afluid outlet 204 of the plurality fluid channels (shown in FIG. 3B) suchthat the plate 122 is maintained at a predetermined temperature. Eachcoil 142 has one or more turns.

FIG. 3A is a schematic perspective view of the plate 122 without theplurality of dielectric plates 150 and each coil 142. FIG. 3B is anegative perspective view of the plate 122 without the plurality ofdielectric plates 150 and each coil 142. The plate 122 includes aplurality of first channels 302. Each first channel of the plurality offirst channels 302 is disposed adjacent to one of the recesses 201. Eachof the recesses 201 is between two adjacent first channels 302 disposedin the plate 122. Each of the first channels 302 is in fluidcommunication with at least one first diffuser inlet of the one or morefirst diffuser inlets 130. In one embodiment, which can be combined withother embodiments described herein, the plate 122 includes a pluralityof second channels 304 disposed in the plate 122. Each second channel ofthe plurality of second channels 304 is disposed between two adjacentcavities 140 of the one or more cavities 140. Each of the secondchannels 304 is in fluid communication with at least second diffuserinlet of the one or more second diffuser inlets 306 formed in the plate122. In another embodiment, which can be combined with other embodimentsdescribed herein, the plate 122 includes a plurality of fluid channels308 of the heat exchange system coupleable to a heat exchanger (notshown). The heat exchanger, such as a chiller, is in fluid communicationwith the plurality of fluid channels 308 via the fluid inlet 202 and thefluid outlet 204. The plurality of fluid channels 308 are disposedadjacent the one or more cavities 140 and exterior recesses of therecesses 201.

FIG. 4 is a schematic bottom view of the plate 122. As shown in FIG. 4 ,each of the first channels 302 and each of the second channels 304 areintersecting. In one embodiment, which can be combined with otherembodiments described herein, each of the first channels 302 areorthogonal to each of the second channels 304. Each of dielectric plates150 is disposed adjacent to adjacent first channels 302 and is disposedadjacent to at least one of the second channels 304. Each first channelof the plurality of first channels 302 includes a plurality of firstholes 402 extending through the plate 122. The flow controllers 141control flow rates of first gases from the first gas source 134 throughthe plurality of first holes 402. The control of the flow rates of firstgases provides independent control of the first gas flows in first zones406 a, 406 b, 406 c, 406 d, 406 e, 406 f, 406 g, 406 h, 406 i(collectively referred to as first zones 406) of the processing region120 corresponding to each first channel of the plurality of firstchannels 302. In the embodiments with the second diffuser 136, which canbe combined with other embodiments described herein, each second channelof the plurality of second channels 304 includes a plurality of secondholes 404 extending through the plate 122. The flow controllers 141control flow rates of second gases from the second gas source 138through the plurality of second holes 404. The control of the flow ratesof second gases provides independent control of the second gas flows insecond zones 408 a, 408 b, 408 c (collectively referred to as secondzones 408) of the processing region 120 corresponding to each secondchannel of the plurality of second channels 304.

In summation, a lid assembly of a chamber for independent control ofplasma density and gas distribution within the interior volume of thechamber is provided. The independent control of the power level andfrequency provided to each coil allows for the density of theinductively coupled plasma to be independently controlled in the processzones corresponding to each coil. The control of the flow rates of firstgases provides independent control of the first gas flows in first zonesof the processing region corresponding to each first channel of theplurality of first channels. The control of the flow rates of secondgases provides independent control of the second gas flows in secondzones of the processing region corresponding to each second channel ofthe plurality of second channels. Uniform gas flow across the processingregion may be desirable in some embodiments. However, in otherembodiments, the gas flow across the processing region may not beuniform. The non-uniform gas flow may be desirable due to some physicalstructure(s) and/or geometry of the chamber.

While the foregoing is directed to embodiments of the presentdisclosure, other and further embodiments of the disclosure may bedevised without departing from the basic scope thereof, and the scopethereof is determined by the claims that follow.

1. A plate for a lid assembly, the plate comprising: a plasma generationsystem, the plasma generation system comprising two or more cavitiesdisposed in parallel in the plate, each cavity of the two or morecavities comprises: a plurality of recesses, each recess of theplurality of recesses having a dielectric plate of a plurality ofdielectric plates disposed therein; a gas distribution assembly, the gasdistribution assembly comprising: a first diffuser, the first diffusercomprises: one or more first diffuser inlets disposed in the plate; anda plurality of first channels in fluid communication with at least oneof the first diffuser inlets, each first channel of the plurality offirst channels is disposed in the plate and is adjacent to at least onerecess of the plurality of recesses; and a second diffuser, the seconddiffuser comprises: one or more second diffuser inlets disposed in theplate and in fluid communication with a plurality of second channels,each of the second channels is intersecting each of the first channels;and each of the dielectric plates is disposed adjacent to adjacent firstchannels and is disposed adjacent to at least one of the secondchannels.
 2. The plate of claim 1, wherein the first diffuser isconfigured to supply one or more first gasses through a plurality offirst holes in each first channel.
 3. The plate of claim 2, furthercomprising a first flow controller disposed between each of the one ormore first diffuser inlets and a first gas source in fluid connectionwith the first diffuser.
 4. The plate of claim 2, wherein the seconddiffuser is configured to supply one or more second gasses through aplurality of second holes in each second channel.
 5. The plate of claim4, further comprising a second flow controller disposed between each ofthe one or more second diffuser inlets and a second gas source in fluidconnection with the second diffuser.
 6. The plate of claim 1, whereinthe plate comprises aluminum-containing materials.
 7. The plate of claim1, wherein the plurality of dielectric plates comprise at least one ofaluminum oxide (Al₂O₃), aluminum nitride (AlN), quartz, zirconiumdioxide (ZrO₂), zirconium nitride (ZrN), quartz, and glass materials. 8.The plate of claim 1, the plasma generation system further comprisingone or more coils positioned on or over the plurality of dielectricplates in a respective cavity.
 9. The plate of claim 1, wherein one ormore of the plurality of first channels are coupled to a first heatexchanger and one or more of the plurality of second channels arecoupled to a second heat exchanger.
 10. The plate of claim 9, whereinthe first heat exchanger is a chiller.
 11. A gas distribution assemblyfor a lid assembly, the gas distribution assembly comprising: a firstdiffuser, the first diffuser comprises: one or more first diffuserinlets disposed in a plate for the lid assembly; and a plurality offirst channels in fluid communication with at least one of the firstdiffuser inlets, each first channel of the plurality of first channelsis disposed in the plate; and a second diffuser, the second diffusercomprises: one or more second diffuser inlets disposed in the plate andin fluid communication with a plurality of second channels, each of thesecond channels is intersecting each of the first channels.
 12. The gasdistribution assembly of claim 11, wherein the first diffuser isconfigured to supply one or more first process gasses through aplurality of first holes in each first channel.
 13. The gas distributionassembly of claim 12, further comprising a flow controller disposedbetween each of the one or more first diffuser inlets and a first gassource in fluid connection with the first diffuser.
 14. The gasdistribution assembly of claim 12, wherein the second diffuser isconfigured to supply one or more second gasses through a plurality ofsecond holes in each second channel.
 15. The gas distribution assemblyof claim 14, further comprising a second flow controller disposedbetween each of the one or more second diffuser inlets and a second gassource in fluid connection with the second diffuser.
 16. The gasdistribution assembly of claim 11, wherein one or more of the pluralityof first channels are coupled to a first heat exchanger and one or moreof the plurality of second channels are coupled to a second heatexchanger.
 17. A gas distribution assembly for a lid assembly, the gasdistribution assembly comprising: a first diffuser, the first diffusercomprises: one or more first diffuser inlets disposed in a plate for thelid assembly; and a plurality of first channels in fluid communicationwith at least one of the first diffuser inlets, each first channel ofthe plurality of first channels is disposed in the plate; a first flowcontroller disposed between each of the one or more first diffuserinlets and a first gas source in fluid connection with the firstdiffuser; and a second diffuser, the second diffuser comprises: one ormore second diffuser inlets disposed in the plate and in fluidcommunication with a plurality of second channels, each of the secondchannels is intersecting each of the first channels; and a second flowcontroller disposed between each of the one or more second diffuserinlets and a second gas source in fluid connection with the seconddiffuser.
 18. The gas distribution assembly of claim 17, wherein thefirst diffuser is configured to supply one or more first gasses througha plurality of first holes in each first channel.
 19. The gasdistribution assembly of claim 17, wherein the second diffuser isconfigured to supply one or more second gasses through a plurality ofsecond holes in each second channel.
 20. The gas distribution assemblyof claim 17, wherein one or more of the plurality of first channels arecoupled to a first heat exchanger and one or more of the plurality ofsecond channels are coupled to a second heat exchanger.